Key Words: Subarachnoid hemorrhage arterial injury reaction. This is a proposal to use an animal model of subarachoid hemorrhage to evaluate a drug which might be effective in preventing the progressive intracranial arterial injury reaction which occurs in response to blood and the associated reduction in cerebral blood flow. The animals will be treated with a drug which is knwon to have a protective effect on arterial injury. An attempt will be made to identify the most effective drug administration schedule.